Foods/Food Additives

Question 1

Grapes and raisins

Answer 1

• acute renal failure in dogs
• toxin principle unknown
• lowest dose: 0.32-0.65g/kg for both red and whites
• symptoms:
• vomiting (usually within first 2 hours)
• diarrhoea
• anorexia
• lethargy
• polydipsia
• renal failure in 24 hours to several days
• Signs:
• consistent with renal failure
• vomiting
• lethargy
• anorexia
• diarrhoea
• abdominal pain
• dehydration
• Serum chemistry
• hypercalcemia
• consistent with renal failure

Tx:

• decontamination with emesis
• AC
• supportive care
• early diuresis can prevent renal failure
• monitor renal chemistry values for 72 hours
• Anuric renal failure: furosemide, dopamine, mannitol
• hemodialysis or peritoneal dialysis can be beneficial
• renal damage can be reversed given enough time and supportive Tx

Question 2

Chocolate

Answer 2

• toxic ingredient: methylxanthines = caffeine and theobromine
• theobromine higher in doses
• they are alkaloids (also found in teas and coffees)
• increase movement of calcium into cells and block adenosine receptors
• causes CNS stimulation and tachycardia
• increases free calcium and thereby increases skeletal and cardiac muscle contractility
• rapidly absorbed in the mouth and eliminated via urine and bile
• more in dark then milk chocolate
• 20mg/kg
• vomiting
• hyperactivity
• increased thirst
• 40-50mg/kg
• tachycardia
• hypertension
• higher doses
• seizures and tremors
• minimum lethal dose
• 100mg/kg
• Signs:
• seen about 6-12 hours post ingestion

Tx:

• decontamination
• AC due to extensive enterohepatic recirculation
• urinary catheter or frequent walks as reabsorption occurs across urinary bladder wall
• diazepam (seizures)
• methocarbamol (tremors)
• may need up to 72 hours

Question 3

Allium (onions, garlic, leek, shallot, chives)

Answer 3

• toxic regardless of raw, cooked or dehydrated
• toxic component: propyl disulfide = produces oxygen free radicals
• enterocytes = oxidative injury and cell membrane damage and intravascular hemolysis
• disulfides
• denature hemoglobin=precipitates and binds to interior of cell membrane forming Heinz bodies= removed by reticuloendothelium and hemolysis
• methemoglobin also produced
• time between ingestion and clinical signs is dose dependent
• as long as 7-10 days
• raw onions 11-15g/kg causes clinical signs
• dehydrated onions can cause signs at 5.5g/kg
• Clinical signs:
• inappetence
• ataxia
• lethargy
• recumbeny
• tacycardia
• tachypnea
• dyspnea
• pale or icteric MM
• vomiting
• diarrhoea
• Lab results
• Heinz bodies
• Howell Jolly bodies
• regenerative anemia
• hemoglobinemia
• hemoglobinuria
• bilirubin and lactate elevations
• Diagnosis
• non
• but onion or garlic odor in breath
• TX:
• cardiovascular support with IVF
• blood products if anemia is severe

Question 4

Xylitol

Answer 4

• rapid drop in BG in dogs
• depression
• ataxia
• seizures
• causes insulin release up to 6X greater than an equal dose of glucose
• rapidly absorbed in GIT
• toxic dose
• 0.1g/kg
• ~0.3g can be found in a stick of gum
• 190g in a cup of granulated xylitol
• clinical signs
• rapid onset (30-60mins)
• can be delayed by 12 hours
• vomiting and lethargy secondary to hypoglycemia
• progresses to ataxia, collapse and seizures ‘
• hypokalemia secondary to intracellular uptake of potassium with insulin
• hypophosphatemia
• liver failure in 12-24 hours
• Clinical and lab findings
• coagulopathy
• increases PT and APTT
• severely increased ALT
• moderately increased bilirubin
• mild thormbocytopenia and mild increase in phosphorus
• presence of phosphatemia = poor prognostic indicator
• dose of >0.5g/kg = hepatotoxic
• Tx:
• decontamination is NOT an option
• baseline BG, serum potassium, phosphorus levels, liver enzymes and coagulation status to assess
• dextrose fluids
• liver protectants
• antioxidants (N-acetylcystine and S-adenosylmethionine)

Question 5

Salt

Answer 5

*home-made play dough
*toxic dose is low
-only small amount needed for potentially lethal dose
-as low as 2g NaCl/kg
*Symptoms:
-vomiting and polydipsia within 3 hours of ingestion
-salt toxicosis:
~dehydration
~or overhydration
~ataxia
~protracted vomiting
~CNS signs
*Tx:
-decontamination by emesis
-Charchoal is not effective and not recommended
-supportive care and Tx for hypernatremia
-restore electrolyte balance and diuresis of excess sodium
*Care must be taken to lower sodium at an appropriate rate
-is too quickly: can cause cerebral edema as water shifts back into the cerebral circulation
Tx:
-IVF with 5% dextrose and loop diuretics to facilitate excretion of sodium with careful management and monitoring of NaCl levels is recommended
-do not lower NaCl by more than 0.5-1.0mEq/L/hr
-maximum 8-12 mEq/L/24 hours
-mannitol and furosemide to Tx cerebral edema

Question 6

Tremogenic mycotoxins

Answer 6

• from fungal metabolism
• mold found in
• garbage and composted food remains
• Penitrem A and Roquefortine = 2 most common
• affect CNS
• easily absorbed and excreted primary in bile = enterohepatic recirculation
• crosses blood brain barrier
• 0.175mg/kg considered toxic dose
• clinical signs:
• within 30min (sometimes 2-3hours)
• Early signs: vomiting, hyperactivity, panting, irritability, weakness, muscle tremors, and rigidity
• Late signs: opisthotonos (muscle spasm), Seizures, nystagmus, recumbency with paddling
• Increased muscle activity:
• hyperthermia
• exhaustion
• metabolic changes
• rhabdomyolysis
• dehydration
• Clinical pathology:
• increased anion gap secondary to lactate accumulation
• Increased muscle activity = increased creatinine, AST and lactic dehydrogenase
• severe fluid loss and dehydration can occur
• Tx:
• stabilise vital signs
• decontamination
• full gastrointestinal lovage
• multiple doses of AC
• diazepam with phenobarbital
• methocarbamol
• good prognosis